A hybrid electric propulsion system is comprised of a multiplicity of power sources combined to provide traction power to the wheels of a vehicle. There are two major types of hybrid electric propulsion systems, Series and Parallel.
Series hybrid technology is based on all electric traction where electrical power is derived from an energy storage source such as a battery and/or capacitor where the energy storage device is charged from the AC mains, regenerative breaking and/or an on board electric generation device.
Parallel hybrid technology is based on the mechanical combination of a multiplicity of power sources in order to generate motive power to the wheels of a vehicle. In a parallel hybrid propulsion system, motive power is typically generated by an internal combustion engine (ICE) with additional mechanical power introduced into the motive system via an electric motor and/or other power source such as a pneumatic motor.
The unique technology being presented herein is based on the use of an automatic transmission which utilizes pressurized fluid and centrifugal force in order to change gears to increase the speed of a vehicle. Most automatic transmissions for medium and heavy-duty weight class vehicles (USDOT Class 6, 7, 8) have a Power Take Off (PTO) gear option.
A PTO gear is a direct connection to the power output of a transmission and is typically connected to the torque converter section of the transmission, which is a 1:1 ratio connection to the crankshaft of the ICE (once the torque converter has locked). The PTO gear is accessible via a cover plate on the external housing of a transmission. The PTO cover is removed and a PTO element is connected to the transmission's PTO gear.
The PTO element is a device having an input gear which meshes with the transmission's PTO gear and has and output shaft which can connect to a u-joint style driveshaft. The PTO output is typically used for driving auxiliaries such as air compressors, water pumps, and/or hydraulic pumps. PTO operation can be achieved in a stationary mode and/or while driving.
In the prior art patents of Gruenwald et al. (U.S. Pat. Nos. 6,484,830, 6,651,759, 7,004,273 and 7,252,165), there is described a hybrid system using ultracapacitors, which couples an AC induction motor through a PTO shaft to use regenerative braking energy to help propel the vehicle